Interstimulus and Inter-Response Time Variables in Reaction Times to Regularly Recurring Visual Stimuli

Abstract

As an addendum to a previous study, it is demonstrated that having Ss react to either every fourth, every second, or every stimulus in a series of regularly recurring flashes of light results in three nearly identical positive linear relationships between reaction time and interstimulus time interval. This similarity of functions is interpreted as being due to covert reacting by S to the stimulus flashes to which no overt reaction is required. As a consequence of such covert responding, readiness to react becomes synchronized with the interstimulus time interval and does not vary appreciably with the inter-response time interval.